Work-holding clamp.



J. M. HARGRAVE.

WORK HOLDING CLAMP- APPLICATION FILED JUNE 21. 1915.

Patented Oct. 17, 1916.

JOHN M. HARGRAVE, OF CINCINNATI, OI-IIO.

WORK-HOLDING CLAMP.

Application filed June 21, 1915.

To all whom it may concern:

Be it known that I, JOHN M. HARGRAVE, a citizen of the United States, and residing at Hyde Park, Cincinnati, in the county of Hamilton and State of Ohio, have invented a new and useful Improvement in Work- Holding Olamps, of which the followlng specification is a full disclosure.

My invention relates to a work clamp of the type comprising a notched bar, a relatively fixed and a relatively adjustable j aw,

the adjustable jaw having a notch engaging pawl to definitely position said jaw on the bar, in a work engaging position for a subsequent clamping of the work by the screw clamp in the fixed jaw.

The object of the invention is to provide a notch engaging pawl which fulcrums on and transmits all clamping strains directly to the jaw member.

.Another object is to provide a notch engaging pawl fulcrumed on the jaw member and retained within the bracket portlon thereof by a transverse pin or stud.

In ordinary types of pawl structures a pivot pin passes through the pawl and is secured in the walls of the bracket, compelling the pivot to assume the strains incident to a clamping operation. To avoid the use of a fulcrum pin and to transmit the strains directly to the aw member, I provide a correlated structure of pawl and jaw member, whereby the pawl fulcrums on an integral portion of the jaw and is retained within the bracket portion thereof by a pin or stud which is subjected to no leverage strains.

The features of the invention are more fully set forth in the description of the accompanying drawings, forming a part of this specification, in which Figure 1 is a side elevation with the wall of the pawl housing broken away. Fig. 2 is a rear view in elevation, showing the notched side of the bar.

The bar 1 has the notched or detent side 2, and the relatively fixed jaw 3, having the screw clamp 4. The coacting jaw 5 is adjustable on the bar, the work engaging por- Specification of Letters Patent.

Patented Oct. 17, 1916.

Serial No. 35,340.

tions 6 of the jaws being on the inside of the bar, the notches being on the outside of the bar. The jaw 5 has a collar portion 7, with the rearward extension 8, comprising a fulcrum shelf or seat 9, formed with a slightly concave surface 10, for seating and supporting the fulcrum elbow or knuckle 11 of the pawl 12. This pawl has the latch or detent end 13 for engaging the notches, and the lever end 1 1. A spring 15 being supported on the shelf under said lever end, to force the pawl end normally inward. The extension 8 has the vertical side walls 16, rising from the seat 9, forming a bracketlike housing or socket for said pawl. The crook of the elbow pawl provides a recess 17 on the other side of the fulcrum portion, through which the retainer 18 passes, its ends being secured in the walls 16, so that said member 18 is positioned crosswise over the medial portion of the pawl, but does not support or sustain the same. The thrust of the pawl leverage is entirely sustained by the jaw extension 8, so that the jaw is very strong'and durable, as well as cheap and efficient, there being no detachable parts to be strained, or wornv out, or renewed.

I claim:

In a work clamp, comprising a notched trio with said seat socket for confining the pawl within the seat socket of said second In witness whereof, I hereunto subscribe my name, as attested by the two subscribing witnesses.

JOHN M. HARGRAVE. Witnesses:

CLARENCE B. FOSTER, L. A. BUCK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

